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Claesen’s for Boys – Underwear, Pajamas & Onesies

From soft boys’ boxers, briefs, singlets, and T-shirts to comfortable boys’ pajamas and playful onesies – Claesen’s boys’ basics combine premium quality, perfect fit, and everyday comfort.
Made from breathable cotton with stretch or warm flannel, our collection is designed for both day and night. Discover durable boys’ essentials that stay soft, keep their shape, and look great wash after wash – ideal for school, play, sleep, and holidays.

Kids UV T-Shirt LS Fish Kids UV T-Shirt LS Fish
Kids UV T-Shirt LS Fish 260500U-Fish
€34.95
UV T-Shirt SS Fish UV T-Shirt SS Fish
UV T-Shirt SS Fish 26050U-Fish
€29.95
UV T-Shirt Short Sleeve Blueberry UV T-Shirt Short Sleeve Blueberry
UV T-Shirt Short Sleeve Blueberry 26050U-Blueberry
€29.95
Kids UV T-Shirt LS Blueberr Kids UV T-Shirt LS Blueberr
Kids UV T-Shirt LS Blueberr 260500U-Blueberry
€34.95
Jongens zwembroek Fish  LF Jongens zwembroek Fish  LF
Jongens zwembroek Fish LF 26045-Fish
€34.95
Jongens zwembroek Fish TF Jongens zwembroek Fish TF
Jongens zwembroek Fish TF 26051-Fish
€29.95
Jongens zwembroek Blueberry LF Jongens zwembroek Blueberry LF
Jongens zwembroek Blueberry LF 26045-Blueberry
€34.95
Jongens zwembroek Blueberry TF Jongens zwembroek Blueberry TF
Jongens zwembroek Blueberry TF 26051-Blueberry
€29.95
Short onesie Shrimp Short onesie Shrimp
Short onesie Shrimp 260316-Shrimp
€39.95
Boys Shortama Shrimp Boys Shortama Shrimp
Boys Shortama Shrimp 260463-Shrimp
€39.95
Hemd 2 pack Shrimp Hemd 2 pack Shrimp
Hemd 2 pack Shrimp 260150-Shrimp
€34.95
Boys Boxer 5-Pack Shrimp
Boys Boxer 5-Pack Shrimp 2602085-Shrimp
€49.95
Onesie Happy Camper Onesie Happy Camper
Onesie Happy Camper 260316-Happycamper
€39.95
Boys Shortama Happy Camper Boys Shortama Happy Camper
Boys Shortama Happy Camper 260463-Happycamper
€39.95
Singlet Happy Camper Singlet Happy Camper
Singlet Happy Camper 260150-HappyCamper
€34.95
Boys Boxer 5 Pack Happy Camper Boys Boxer 5 Pack Happy Camper
Boys Boxer 5 Pack Happy Camper 2602085-Happycamper
€49.95
Terry Shortama Blueberry Terry Shortama Blueberry
Terry Shortama Blueberry 260919U-Blueberry
€39.95
Bathcape Fish Bathcape Fish
Bathcape Fish 2609461-Fish
€39.95
Terry onesie Fish Terry onesie Fish
Terry onesie Fish 2609181U-Fish
€49.95
Terry Poncho Blueberry Terry Poncho Blueberry
Terry Poncho Blueberry 2609461-Blueberry
€39.95
Terry onesie Blueberry Terry onesie Blueberry
Terry onesie Blueberry 2609181U-Blueberry
€49.95
Terry Shortama Fish Terry Shortama Fish
Terry Shortama Fish 260919U-Fish
€39.95
Socks 2 pack Cloudberry blue Socks 2 pack Cloudberry blue
Socks 2 pack Cloudberry blue CL100-Cloudberryblue
€21.95
Socks 2-Pack Mint Leaf Socks 2-Pack Mint Leaf
Socks 2-Pack Mint Leaf CL100-Mintleaf
€21.95
Pyjama Cloudberry Blue Pyjama Cloudberry Blue
Pyjama Cloudberry Blue CL333-Cloudberryblue
€39.95
Pyjama Mint Leave Pyjama Mint Leave
Pyjama Mint Leave CL333-Mintleaf
€39.95
Singlet 1 pack Cloudberry blue Singlet 1 pack Cloudberry blue
Singlet 1 pack Cloudberry blue CL150-Cloudberryblue
€18.95

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Boys’ Underwear and Pajamas

Premium, comfortable, and durable boys’ underwear and boys’ pajamas – designed to be worn all day, not just under clothes or in bed. That’s what Claesen’s has been known for over 25 years. Our collections combine a refined look & feel with strong materials and fresh seasonal designs: classic, sporty, colorful, and timeless basics.

Every boy is different. That’s why Claesen’s offers a wide range of boys’ boxers, briefs, singlets, T-shirts, pajamas, shortamas, pajama sets, and onesies. For younger kids and older boys alike. For sleeping, playing, relaxing, and everything in between.

High-Quality Boys’ Underwear and Sleepwear

All Claesen’s boys’ collections are made from high-quality cotton with stretch. Cotton is breathable, soft, and moisture-absorbing, while elastane provides flexibility and freedom of movement. Perfect for active days, relaxing moments, or a comfortable night’s sleep.

Both our boys’ underwear and pajamas are designed with a perfect fit that lasts, even after frequent washing. We work exclusively with trusted factories that ensure safe working conditions, avoid harmful chemicals, and follow strict textile standards such as OEKO-TEX® certification.

Claesen’s Boys’ Basic Underwear

Claesen’s boys’ basic underwear stands out through simplicity and quality. Think comfortable boys’ briefs, boxers, singlets, and T-shirts in clean, timeless colors, without unnecessary details. Minimalist, durable, and focused on everyday comfort.

Our basics are available in sizes from 92 up to 170 and are always in stock in essential colors such as white, black, grey, and navy. Ideal as daily underwear for school, sports, or sleep.

Wide Range of Styles and Fits

From classic boys’ briefs to modern boxers, there is a wide choice of styles. Our singlets and T-shirts are designed to be versatile and can easily be worn as outerwear, especially during warmer days.

The boys’ pajama collection changes every season and includes pajama sets, shortamas, button-up styles, pull-over designs, and the iconic Claesen’s onesies. Perfect for home, holidays, camping, or after swimming.

Prints and Colors for Boys

From subtle basics to playful designs, Claesen’s offers prints for every boy. Choose from solid colors, animal prints, graphic patterns, nature-inspired designs, and creative seasonal themes.

Whether calm, bold, or expressive – there is always a style that fits every age and personality. Discover boys’ underwear and pajamas that combine comfort, durability, and style, designed to stay soft and look great wash after wash.